Policy makers and utilities need robust energy system models to determine the best strategies to decarbonize the world’s electric grids. But most existing models were designed for grids operating more than a decade ago. Today’s grids are much different. New technologies such as solar power and grid energy storage are being rapidly deployed. To accommodate these and other technologies, utilities must run grids in completely new ways.
Improvements are needed in energy system models so that they adequately account for these significant changes. Without these crucial updates, the models may lead to decarbonization strategies and infrastructure investments that compromise grid reliability and make power less affordable for consumers.
Leading modeling experts from the U.S. Department of Energy’s (DOE) Argonne National Laboratory and several other institutions call attention to the urgent need for better energy system models in a recent Nature Energy paper. Their objective was to inform researchers, regulators, policymakers, industry and funding agencies about opportunities to enhance the models.
The paper focuses specifically on capacity expansion models, which are tools used to simulate future grids and identify optimal investments over multi-year periods. These models account for a complex set of factors, such as new policies, technology advances and electricity demand forecasts. Electric utilities use the models in long-term grid planning. Regulators and other governmental agencies use them to evaluate new energy and environmental policies.
Energy storage: A key enabler of grid decarbonization
To address climate change, governments and companies around the world have committed to net-zero greenhouse gas emissions by mid-century. These commitments have facilitated rapid deployment of solar and wind power.
Solar and wind generation are variable depending on when the sun shines and wind blows. That means more flexible energy resources are needed to balance energy supply and demand and maintain grid reliability.
Batteries and other energy storage technologies are widely viewed as key providers of this flexibility. They can store excess energy during periods of high solar and wind generation and release energy during low generation periods. Grid operators also envision the use of storage to ensure energy availability during extreme weather.
“Energy storage is fundamentally changing how the grid is operated,” said Todd Levin, Argonne’s electricity markets team lead and one of the paper’s authors. “Historically, grid operators have had to precisely balance generation and consumption of energy in real-time. By moving energy through time, energy storage enables a grid that doesn’t need to generate electricity in the same second that it’s used.”
Increasingly, policymakers are applying capacity expansion models to inform decisions on decarbonization pathways and associated investments. But existing models are not designed for grids that rely on energy storage to integrate large amounts of variable renewable energy resources.
According to the paper, models don’t accurately represent the technical and economic characteristics of energy storage. Additionally, they do not account for the interactions between storage and other grid components, such as wind and solar power plants. What’s more, they don’t properly incorporate the value of energy storage in its various grid and electricity market uses.